1. Field of the Invention
The present invention relates to benastatins A and B, which are novel, physiologically active substances having an anti-glutathione transferase activity, an immunomodifier activity and a microorganism-controlling actvity, and also to the production and the use thereof.
2. Related Art Statement
Glutathione transferase is an enzyme locally present in cell membranes and cytoplasms.
It is known that cell membrane enzyme inhibitors have an immunomodifier activity [T. Aoyagi, "Protease inhibitor and biological control", Bioactive Metabolites from Microorganisms, ed. by M. E. Bushell and U. Gafe, pp. 403-418, Elsevier Science Publishers B.V., Amsterdam, (1989)]. It may therefore be expected that a glutathione transferase inhibitor would also have an immunomodifier activity.
It is also known that membrane-connecting glutathione transferases have an activity as leukotriene C.sub.4 synthesis enzymes, and have a close relation with inflammations and allergic reactions [Tanpakushitsu, Kakusan, Kouso (Proteins, Nucleic Acids and Enzymes), 33, 1564-1573 (1988)].
Furthermore, it is reported that cytoplasmic glutathione transferases have a close relation with the resistance mechanism of anticancer agent-resistant tumor cells [Gan-to Kagaku Ryoho (Cancers and Chemotherapies), 16, 592-598 (1989)].
Known glutathione transferase inhibitors include indomethacin, meclofenamic acid and the like [Biochemical and Biophysical Research Communications, 112, 980-985 (1983)].
Known glutathione transferase inhibitors such as indomethacin and meclofenamic acid, etc., have a low specificity to glutathione transferases. It is therefore desired to provide an inhibitor substance highly specific to glutathione transferases.